[igt-dev] [RFC PATCH v10 2/6] lib/i915: add gem_engine_topology library

[Chris Wilson]

Quoting Andi Shyti (2019-03-05 13:16:07)
> The gem_engine_topology library is a set of functions that
> interface with the query and getparam/setparam ioctls.
> 
> The library's three main access points are:
> 
>  - get_active_engines()
>  - gem_set_context_get_engines()
>  - igt_require_gem_engine_list()
> 
> The first two functions are similar, with the difference that the
> 'gem_set_context_get_engines()' sets the engine before returning
> the engine list in a 'intel_execution_engine2' type array.
> Another improtant difference is that the first function works
> only with the getparam/setparam and query ioctls are implemented
> and it return 'NULL' in the other case.
> 
> 'gem_set_context_get_engines()' function, at the first call
> generates the array of active engines (either physical or
> virtual) called 'intel_active_engines2'.
> If the driver cannot be queried, the 'intel_active_engines2'
> array points to the exisiting 'intel_execution_engines2' which
> has been previously defined.
> 
> The value of the 'intel_active_engines2' will be used in further
> calls to check whether the above mentioned ioctls are implemented
> without the need to call getparam().
> 
> The 'igt_require_gem_engine_list()' causes the test to fail in
> case the required ioctls are not implemented.
> 
> Signed-off-by: Andi Shyti <andi.shyti at intel.com>
> ---
>  lib/Makefile.sources           |   2 +
>  lib/i915/gem_engine_topology.c | 199 +++++++++++++++++++++++++++++++++
>  lib/i915/gem_engine_topology.h |  39 +++++++
>  lib/igt_gt.c                   |   2 +-
>  lib/igt_gt.h                   |   2 +-
>  lib/meson.build                |   1 +
>  6 files changed, 243 insertions(+), 2 deletions(-)
>  create mode 100644 lib/i915/gem_engine_topology.c
>  create mode 100644 lib/i915/gem_engine_topology.h
> 
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index cf2720981707..757bd7a17ebe 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -13,6 +13,8 @@ lib_source_list =             \
>         i915/gem_ring.c \
>         i915/gem_mman.c \
>         i915/gem_mman.h \
> +       i915/gem_engine_topology.c      \
> +       i915/gem_engine_topology.h      \
>         i915_3d.h               \
>         i915_reg.h              \
>         i915_pciids.h           \
> diff --git a/lib/i915/gem_engine_topology.c b/lib/i915/gem_engine_topology.c
> new file mode 100644
> index 000000000000..9376b4792441
> --- /dev/null
> +++ b/lib/i915/gem_engine_topology.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include "drmtest.h"
> +#include "igt_gt.h"
> +#include "ioctl_wrappers.h"
> +
> +#include "i915/gem_engine_topology.h"
> +
> +#define SIZEOF_CTX_PARAM       offsetof(struct i915_context_param_engines, \
> +                                       class_instance[I915_EXEC_RING_MASK + 1])
> +#define SIZEOF_QUERY           offsetof(struct drm_i915_query_engine_info, \
> +                                       engines[I915_EXEC_RING_MASK + 1])
> +
> +static struct intel_execution_engine2 *intel_active_engines2;
> +
> +int __gem_query(int fd, struct drm_i915_query *q)
> +{
> +       int err = 0;
> +
> +       if (igt_ioctl(fd, DRM_IOCTL_I915_QUERY, q))
> +               err = -errno;
> +
> +       errno = 0;
> +       return err;
> +}
> +
> +void gem_query(int fd, struct drm_i915_query *q)
> +{
> +       igt_assert_eq(__gem_query(fd, q), 0);
> +}
> +
> +static void query_engines(int fd,
> +                         struct drm_i915_query_engine_info *query_engines)
> +{
> +       struct drm_i915_query_item item = { };
> +       struct drm_i915_query query = { };
> +
> +       item.query_id = DRM_I915_QUERY_ENGINE_INFO;
> +       query.items_ptr = to_user_pointer(&item);
> +       query.num_items = 1;
> +       item.length = SIZEOF_QUERY;
> +
> +       item.data_ptr = to_user_pointer(query_engines);
> +
> +       gem_query(fd, &query);
> +}
> +
> +bool gem_has_engine_topology(void)
> +{
> +       return intel_active_engines2 != intel_execution_engines2;
> +}
> +
> +static void set_ctx_param_engines(int fd, uint32_t ctx_id)
> +{
> +       struct i915_context_param_engines *ctx_engine;
> +       struct drm_i915_gem_context_param ctx_param;
> +       const struct intel_execution_engine2 *e2;
> +       uint8_t buff[SIZEOF_CTX_PARAM] = { };
> +       int i;
> +
> +       if (!gem_has_engine_topology())
> +               return;

Why would different fd have the same topology?
-Chris